Preparation

To make breadcrumbs, grate bread through the large holes of a box grater; place the crumbs in a small bowl and toss with 2 teaspoons oil.

Heat the remaining 2 teaspoons oil in a medium nonstick skillet over medium heat. Add shallot and cook, stirring, until softened, 2 to 3 minutes. Pour in lemon juice and bring to a boil, stirring gently; remove from the heat and add butter. Swirl the pan, letting the butter melt and slightly thicken the sauce. Stir in capers.

Sprinkle fish with salt and place in the prepared baking dish. Pour the pan sauce over the fish and sprinkle with the breadcrumbs.

Bake the fish until it is opaque in the center, 15 to 18 minutes. Serve each portion topped with about 3 tablespoons pickled beets.

Make Ahead Tip: Prepare the breadcrumbs (Step 2) up to 2 days ahead; store at room temperature in a plastic bag.

Ingredient Note: Just about any fish will take to this treatment beautifully. If using halibut, ask for wild-caught fish from the Pacific; it is more sustainably fished and has a larger, more stable population, according to the Monterey Bay Aquarium Seafood Watch (mbayaq.org/cr/seafoodwatch.asp).